找不到gradle signingconfigs

在我的应用程序中，我想创建调试和发布构建类型

这是我的gradle代码

apply plugin: 'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.1"

    defaultConfig {
        applicationId "com.pmbo.android.pmb"
        minSdkVersion 15
        targetSdkVersion 21
        versionCode 10001
        versionName "1.0"
    }


    signingConfigs {
        myConfigs{
            storeFile file("ncv.jks");
            storePassword("qwerty");
            keyAlias("MyNewApp");
            keyPassword("qwerty");
        }
    }

    buildTypes {
        release {
            minifyEnabled false
            debuggable false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            signingConfig singningConfigs.myConfigs

        }

        debug {
            debuggable true
            applicationIdSuffix ".debug"
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.google.android.gms:play-services:6.5.87'
    compile 'com.google.code.gson:gson:2.3.1'
}

每当我尝试构建gradle时，我都会遇到此错误

Error:(30, 0) Could not find property 'singningConfigs' on BuildType_Decorated{name=release, debuggable=false, testCoverageEnabled=false, jniDebuggable=false, pseudoLocalesEnabled=false, renderscriptDebuggable=false, renderscriptOptimLevel=3, applicationIdSuffix=null, versionNameSuffix=null, minifyEnabled=false, zipAlignEnabled=true, signingConfig=null, embedMicroApp=true, mBuildConfigFields={}, mResValues={}, mProguardFiles=[/Users/pmb/opt/sdk/tools/proguard/proguard-android.txt, /Users/pmb/Documents/MyProjects/PMBO/app/proguard-rules.pro], mConsumerProguardFiles=[], mManifestPlaceholders={}}.

我不是我做错了什么，而是四处张望，无法找出问题所在。

如图所示，我的.jks文件在我的应用程序模块中。

谁能告诉我我做错了什么？